Hey,
I have the same issue. Did you manage to solve it somehow? I’ve tried looking for solutions. The Spacewar is used by steam to demonstrate their API to developers. So if our game has the same default SteamAppId (480) other players on Steam see it Spacewar, and that’s what they get to download/play.
However, if I change the SteamAppId (both in the NetworkManager > Fizzy Steamworks component and in the steam_appid.txt file), then my friend can only watch my game (empty screen) because the Lobby isn’t created. I can only enter the Host/Join screen, choose to host and then the screen is empty, because that OnLobbyCreated callback is never called.
According to what I understand from Steam forums and guides, the SteamAppId should be my app commercial id after I register with Steam. But in our case it’s a “pirated” game - just for the relay.
Is there anyone following this course that has managed to host the game on Steam and invite a different user through Steam, without the other player having the game as well already?